The invention relates to heat dissipation and is particularly concerned with heat transfer between electronic components and heat sinks.
In electronics systems, such as printed circuit boards carrying electronic components, heat is generated by the components in use and it is necessary to remove or dissipate heat to prevent over heating which could result in breakdown of one or more of the components and/or create a fire hazard. To remove or dissipate heat, heat sinks have been implemented.
To ensure that heat flows from the electronic components to the heat sink, a heat transfer medium is typically interposed between the components and the heat sink, since it would otherwise be difficult to ensure proper contact between the electronic components and the heat sink. One type of heat transfer medium used has been non-electrically conductive matrix resin. Because of the risk of a short circuit in an electronic system if the heat transfer medium is electrically conductive, non-electrically conductive media, such as that noted above, have been used. However, non-electrically conductive media are typically relatively poor thermal conductors. Accordingly, it would be desirable to achieve better thermal conductivity between electronic components and a heat sink.
According to a first aspect, the invention provides a method for creating a thermally conductive path between a component of a printed circuit board and a heat sink using an electrical insulator material and a thermally conductive material. The electrical insulator material is adhesive, to assist in adhering surfaces against which it is applied. Typically, the circuit board is affixed to the heat sink, creating a gap between the component and the heat sink. The electrical insulator material is applied in the gap. Then, the thermally conductive material is applied within the electrical insulator material, causing the thermally conductive material to spread beyond the perimeter of the electrical insulator material. The electrical insulator material confines the thermally conductive material within the gap in thermally conductive contact between the electronic component and the heat sink.
According to another aspect, the invention provides a method for creating a thermally conductive path between a component of a printed circuit board and a heat sink using a electrical insulator material and a thermally conductive material. The electrical insulator material is adhesive, to assist in adhering surfaces against which it is applied. The electrical insulator material is applied to either the heat sink or the electronic component (or a covering of either the heat sink or the electronic component). Then, the thermally conductive material is applied within or on top of the electrical insulator material. The printed circuit board is then affixed to the heat sink, such that the thermally conductive material creates a thermally conductive path from the component to the heat sink. The electrical insulator material confines the thermally conductive material to a volume between the electronic component and the heat sink.
According to another aspect, the invention provides an electronics system having a heat sink structure and a printer circuit board structure. The circuit board structure has a printed circuit board with at least one electronic component mounted thereon. The heat sink structure and the circuit board structure are affixed to each other with a gap between the electronic component and the heat sink structure. The electronics system has a means for creating a thermally conductive path from the heat sink structure to the electronic component. The means comprises both a good thermally conductive, electrically conductive material and an electrical insulator material between the electronic component and the heat sink structure with the good thermally conductive electrically conductive material being confined by the electrical insulator.
Advantageously, different embodiments of the present invention may permit: improved thermal conductivity or heat dissipation between electronic components on a printed circuit board and a heat sink; and/or electrical grounding of the electronic components to the heat sink.